Add sysdeps/ieee754/soft-fp.

The default sysdeps/ieee754 fma implementations rely on exceptions and
rounding modes to achieve correct results through internal use of
round-to-odd.  Thus, glibc configurations without support for
exceptions and rounding modes instead need to use implementations of
fma based on soft-fp.

At present, this is achieved via having implementation files in
soft-fp/ that are #included by sysdeps files for each glibc
configuration that needs them.  In general this means such a
configuration has its own s_fma.c and s_fmaf.c.

TS 18661-1 adds functions that do an operation (+ - * / sqrt fma) on
arguments wider than the return type, with a single rounding of the
infinite-precision result to that return type.  These are also
naturally implemented using round-to-odd on platforms with hardware
support for rounding modes and exceptions but lacking hardware support
for these narrowing operations themselves.  (Platforms that have
direct hardware support for such narrowing operations include at least
ia64, and Power ISA 2.07 or later, which I think means POWER8 or
later.)

So adding the remaining TS 18661-1 functions would mean at least six
narrowing function implementations (fadd fsub fmul fdiv ffma fsqrt),
with aliases for other types and further implementations in some
configurations, that need to be overridden for configurations lacking
hardware exceptions and rounding modes.  Requiring all such
configurations (currently seven of them) to have their own source
files for all those functions seems undesirable.

Thus, this patch adds a directory sysdeps/ieee754/soft-fp to contain
libm function implementations based on soft-fp.  This directory is
then used via Implies from all the configurations that need it, so no
more files need adding to every such configuration when adding more
functions with soft-fp implementations.  A configuration can still
selectively #include a particular file from this directory if desired;
thus, the MIPS #include of the fmal implementation is retained, since
that's appropriate even for hard float (because long double is always
implementated in software for MIPS64, so the soft-fp implementation of
fmal is better than the ldbl-128 one).

This also provides additional motivation for my recent patch removing
--with-fp / --without-fp: previously there was no need for correct use
of --without-fp for no-FPU ARM or SH3, and now we have autodetection
nofpu/ sysdeps directories can be used by this patch for those
configurations without imposing any new requirements on how glibc is
configured.

(The mips64/*/fpu/s_fma.c files added by this patch are needed to keep
the dbl-64 version of fma for double, rather than the ldbl-128 one,
used in that case.)

Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by this patch.

	* soft-fp/fmadf4.c: Move to ....
	* sysdeps/ieee754/soft-fp/s_fma.c: ... here.
	* soft-fp/fmasf4.c: Move to ....
	* sysdeps/ieee754/soft-fp/s_fmaf.c: ... here.
	* soft-fp/fmatf4.c: Move to ....
	* sysdeps/ieee754/soft-fp/s_fmal.c: ... here.
	* sysdeps/ieee754/soft-fp/Makefile: New file.
	* sysdeps/arm/preconfigure.ac: Define with_fp_cond.
	* sysdeps/arm/preconfigure: Regenerated.
	* sysdeps/arm/nofpu/Implies: New file.
	* sysdeps/arm/s_fma.c: Remove file.
	* sysdeps/arm/s_fmaf.c: Likewise.
	* sysdeps/m68k/coldfire/nofpu/Implies: New file.
	* sysdeps/m68k/coldfire/nofpu/s_fma.c: Remove file.
	* sysdeps/m68k/coldfire/nofpu/s_fmaf.c: Likewise.
	* sysdeps/microblaze/Implies: Add ieee754/soft-fp.
	* sysdeps/microblaze/s_fma.c: Remove file.
	* sysdeps/microblaze/s_fmaf.c: Likewise.
	* sysdeps/mips/mips32/nofpu/Implies: New file.
	* sysdeps/mips/mips64/n32/fpu/s_fma.c: Likewise.
	* sysdeps/mips/mips64/n32/nofpu/Implies: Likewise.
	* sysdeps/mips/mips64/n64/fpu/s_fma.c: Likewise.
	* sysdeps/mips/mips64/n64/nofpu/Implies: Likewise.
	* sysdeps/mips/ieee754/s_fma.c: Remove file.
	* sysdeps/mips/ieee754/s_fmaf.c: Likewise.
	* sysdeps/mips/ieee754/s_fmal.c: Update include for move of fmal
	implementation.
	* sysdeps/nios2/Implies: Add ieee754/soft-fp.
	* sysdeps/nios2/s_fma.c: Remove file.
	* sysdeps/nios2/s_fmaf.c: Likewise.
	* sysdeps/sh/nofpu/Implies: New file.
	* sysdeps/sh/s_fma.c: Remove file.
	* sysdeps/sh/s_fmaf.c: Likewise.
	* sysdeps/tile/Implies: Add ieee754/soft-fp.
	* sysdeps/tile/s_fma.c: Remove file.
	* sysdeps/tile/s_fmaf.c: Likewise.

32 files changed, 219 insertions, 39 deletions

diff --git a/sysdeps/arm/nofpu/Implies b/sysdeps/arm/nofpu/Implies
new file mode 100644
index 0000000000..abcbadb25f
--- /dev/null
+++ b/sysdeps/arm/nofpu/Implies
@@ -0,0 +1 @@
+ieee754/soft-fp
diff --git a/sysdeps/arm/preconfigure b/sysdeps/arm/preconfigure
index 33e9501c4f..d803256d9f 100644
--- a/sysdeps/arm/preconfigure
+++ b/sysdeps/arm/preconfigure
@@ -52,4 +52,5 @@ $as_echo "$as_me: WARNING: arm/preconfigure: Did not find ARM architecture type;
   esac
 
   machine=arm/$machine
+  with_fp_cond="!defined __SOFTFP__"
 esac
diff --git a/sysdeps/arm/preconfigure.ac b/sysdeps/arm/preconfigure.ac
index 20de5bcfea..43d014031d 100644
--- a/sysdeps/arm/preconfigure.ac
+++ b/sysdeps/arm/preconfigure.ac
@@ -47,4 +47,5 @@ arm*)
   esac
 
   machine=arm/$machine
+  with_fp_cond="!defined __SOFTFP__"
 esac
diff --git a/sysdeps/arm/s_fma.c b/sysdeps/arm/s_fma.c
deleted file mode 100644
index dc4e27bfc1..0000000000
--- a/sysdeps/arm/s_fma.c
+++ /dev/null
@@ -1,5 +0,0 @@
-#ifdef __SOFTFP__
-# include <soft-fp/fmadf4.c>
-#else
-# include <sysdeps/ieee754/dbl-64/s_fma.c>
-#endif
diff --git a/sysdeps/arm/s_fmaf.c b/sysdeps/arm/s_fmaf.c
deleted file mode 100644
index 550d8b85d3..0000000000
--- a/sysdeps/arm/s_fmaf.c
+++ /dev/null
@@ -1,5 +0,0 @@
-#ifdef __SOFTFP__
-# include <soft-fp/fmasf4.c>
-#else
-# include <sysdeps/ieee754/dbl-64/s_fmaf.c>
-#endif
diff --git a/sysdeps/ieee754/soft-fp/Makefile b/sysdeps/ieee754/soft-fp/Makefile
new file mode 100644
index 0000000000..ada13e8b70
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/Makefile
@@ -0,0 +1,3 @@
+ifeq ($(subdir),math)
+CPPFLAGS += -I../soft-fp
+endif
diff --git a/sysdeps/ieee754/soft-fp/s_fma.c b/sysdeps/ieee754/soft-fp/s_fma.c
new file mode 100644
index 0000000000..313547d061
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_fma.c
@@ -0,0 +1,68 @@
+/* Implement fma using soft-fp.
+   Copyright (C) 2013-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file into
+   combinations with other programs, and to distribute those
+   combinations without any restriction coming from the use of this
+   file.  (The Lesser General Public License restrictions do apply in
+   other respects; for example, they cover modification of the file,
+   and distribution when not linked into a combine executable.)
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <libc-diag.h>
+#include <libm-alias-double.h>
+
+/* R_e is not set in cases where it is not used in packing, but the
+   compiler does not see that it is set in all cases where it is
+   used, resulting in warnings that it may be used uninitialized.
+   The location of the warning differs in different versions of GCC,
+   it may be where R is defined using a macro or it may be where the
+   macro is defined.  */
+DIAG_PUSH_NEEDS_COMMENT;
+DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
+
+#include "soft-fp.h"
+#include "double.h"
+
+double
+__fma (double a, double b, double c)
+{
+  FP_DECL_EX;
+  FP_DECL_D (A);
+  FP_DECL_D (B);
+  FP_DECL_D (C);
+  FP_DECL_D (R);
+  double r;
+
+  FP_INIT_ROUNDMODE;
+  FP_UNPACK_D (A, a);
+  FP_UNPACK_D (B, b);
+  FP_UNPACK_D (C, c);
+  FP_FMA_D (R, A, B, C);
+  FP_PACK_D (r, R);
+  FP_HANDLE_EXCEPTIONS;
+
+  return r;
+}
+DIAG_POP_NEEDS_COMMENT;
+
+#ifndef __fma
+libm_alias_double (__fma, fma)
+#endif
diff --git a/sysdeps/ieee754/soft-fp/s_fmaf.c b/sysdeps/ieee754/soft-fp/s_fmaf.c
new file mode 100644
index 0000000000..295223da50
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_fmaf.c
@@ -0,0 +1,68 @@
+/* Implement fmaf using soft-fp.
+   Copyright (C) 2013-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file into
+   combinations with other programs, and to distribute those
+   combinations without any restriction coming from the use of this
+   file.  (The Lesser General Public License restrictions do apply in
+   other respects; for example, they cover modification of the file,
+   and distribution when not linked into a combine executable.)
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <libc-diag.h>
+#include <libm-alias-float.h>
+
+/* R_e is not set in cases where it is not used in packing, but the
+   compiler does not see that it is set in all cases where it is
+   used, resulting in warnings that it may be used uninitialized.
+   The location of the warning differs in different versions of GCC,
+   it may be where R is defined using a macro or it may be where the
+   macro is defined.  */
+DIAG_PUSH_NEEDS_COMMENT;
+DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
+
+#include "soft-fp.h"
+#include "single.h"
+
+float
+__fmaf (float a, float b, float c)
+{
+  FP_DECL_EX;
+  FP_DECL_S (A);
+  FP_DECL_S (B);
+  FP_DECL_S (C);
+  FP_DECL_S (R);
+  float r;
+
+  FP_INIT_ROUNDMODE;
+  FP_UNPACK_S (A, a);
+  FP_UNPACK_S (B, b);
+  FP_UNPACK_S (C, c);
+  FP_FMA_S (R, A, B, C);
+  FP_PACK_S (r, R);
+  FP_HANDLE_EXCEPTIONS;
+
+  return r;
+}
+DIAG_POP_NEEDS_COMMENT;
+
+#ifndef __fmaf
+libm_alias_float (__fma, fma)
+#endif
diff --git a/sysdeps/ieee754/soft-fp/s_fmal.c b/sysdeps/ieee754/soft-fp/s_fmal.c
new file mode 100644
index 0000000000..79be52c4f1
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_fmal.c
@@ -0,0 +1,66 @@
+/* Implement fmal using soft-fp.
+   Copyright (C) 2013-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   In addition to the permissions in the GNU Lesser General Public
+   License, the Free Software Foundation gives you unlimited
+   permission to link the compiled version of this file into
+   combinations with other programs, and to distribute those
+   combinations without any restriction coming from the use of this
+   file.  (The Lesser General Public License restrictions do apply in
+   other respects; for example, they cover modification of the file,
+   and distribution when not linked into a combine executable.)
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <libc-diag.h>
+#include <libm-alias-ldouble.h>
+
+/* R_e is not set in cases where it is not used in packing, but the
+   compiler does not see that it is set in all cases where it is
+   used, resulting in warnings that it may be used uninitialized.
+   The location of the warning differs in different versions of GCC,
+   it may be where R is defined using a macro or it may be where the
+   macro is defined.  */
+DIAG_PUSH_NEEDS_COMMENT;
+DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
+
+#include "soft-fp.h"
+#include "quad.h"
+
+long double
+__fmal (long double a, long double b, long double c)
+{
+  FP_DECL_EX;
+  FP_DECL_Q (A);
+  FP_DECL_Q (B);
+  FP_DECL_Q (C);
+  FP_DECL_Q (R);
+  long double r;
+
+  FP_INIT_ROUNDMODE;
+  FP_UNPACK_Q (A, a);
+  FP_UNPACK_Q (B, b);
+  FP_UNPACK_Q (C, c);
+  FP_FMA_Q (R, A, B, C);
+  FP_PACK_Q (r, R);
+  FP_HANDLE_EXCEPTIONS;
+
+  return r;
+}
+DIAG_POP_NEEDS_COMMENT;
+
+libm_alias_ldouble (__fma, fma)
diff --git a/sysdeps/m68k/coldfire/nofpu/Implies b/sysdeps/m68k/coldfire/nofpu/Implies
new file mode 100644
index 0000000000..abcbadb25f
--- /dev/null
+++ b/sysdeps/m68k/coldfire/nofpu/Implies
@@ -0,0 +1 @@
+ieee754/soft-fp
diff --git a/sysdeps/m68k/coldfire/nofpu/s_fma.c b/sysdeps/m68k/coldfire/nofpu/s_fma.c
deleted file mode 100644
index d9613fa67c..0000000000
--- a/sysdeps/m68k/coldfire/nofpu/s_fma.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <soft-fp/fmadf4.c>
diff --git a/sysdeps/m68k/coldfire/nofpu/s_fmaf.c b/sysdeps/m68k/coldfire/nofpu/s_fmaf.c
deleted file mode 100644
index aa5c9b2d91..0000000000
--- a/sysdeps/m68k/coldfire/nofpu/s_fmaf.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <soft-fp/fmasf4.c>
diff --git a/sysdeps/microblaze/Implies b/sysdeps/microblaze/Implies
index 73c766c52e..746b21ad66 100644
--- a/sysdeps/microblaze/Implies
+++ b/sysdeps/microblaze/Implies
@@ -1,4 +1,5 @@
 wordsize-32
 # MicroBlaze uses IEEE 754 floating point.
+ieee754/soft-fp
 ieee754/flt-32
 ieee754/dbl-64
diff --git a/sysdeps/microblaze/s_fma.c b/sysdeps/microblaze/s_fma.c
deleted file mode 100644
index d9613fa67c..0000000000
--- a/sysdeps/microblaze/s_fma.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <soft-fp/fmadf4.c>
diff --git a/sysdeps/microblaze/s_fmaf.c b/sysdeps/microblaze/s_fmaf.c
deleted file mode 100644
index aa5c9b2d91..0000000000
--- a/sysdeps/microblaze/s_fmaf.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <soft-fp/fmasf4.c>
diff --git a/sysdeps/mips/ieee754/s_fma.c b/sysdeps/mips/ieee754/s_fma.c
deleted file mode 100644
index 574141416b..0000000000
--- a/sysdeps/mips/ieee754/s_fma.c
+++ /dev/null
@@ -1,5 +0,0 @@
-#ifdef __mips_hard_float
-# include <sysdeps/ieee754/dbl-64/s_fma.c>
-#else
-# include <soft-fp/fmadf4.c>
-#endif
diff --git a/sysdeps/mips/ieee754/s_fmaf.c b/sysdeps/mips/ieee754/s_fmaf.c
deleted file mode 100644
index 30bcdae620..0000000000
--- a/sysdeps/mips/ieee754/s_fmaf.c
+++ /dev/null
@@ -1,5 +0,0 @@
-#ifdef __mips_hard_float
-# include <sysdeps/ieee754/dbl-64/s_fmaf.c>
-#else
-# include <soft-fp/fmasf4.c>
-#endif
diff --git a/sysdeps/mips/ieee754/s_fmal.c b/sysdeps/mips/ieee754/s_fmal.c
index 6b83e914fe..c52331967d 100644
--- a/sysdeps/mips/ieee754/s_fmal.c
+++ b/sysdeps/mips/ieee754/s_fmal.c
@@ -4,4 +4,4 @@
 # error "long double fma being compiled for o32 ABI"
 #endif
 
-#include <soft-fp/fmatf4.c>
+#include <sysdeps/ieee754/soft-fp/s_fmal.c>
diff --git a/sysdeps/mips/mips32/nofpu/Implies b/sysdeps/mips/mips32/nofpu/Implies
new file mode 100644
index 0000000000..abcbadb25f
--- /dev/null
+++ b/sysdeps/mips/mips32/nofpu/Implies
@@ -0,0 +1 @@
+ieee754/soft-fp
diff --git a/sysdeps/mips/mips64/n32/fpu/s_fma.c b/sysdeps/mips/mips64/n32/fpu/s_fma.c
new file mode 100644
index 0000000000..b61fa643de
--- /dev/null
+++ b/sysdeps/mips/mips64/n32/fpu/s_fma.c
@@ -0,0 +1 @@
+#include <sysdeps/ieee754/dbl-64/s_fma.c>
diff --git a/sysdeps/mips/mips64/n32/nofpu/Implies b/sysdeps/mips/mips64/n32/nofpu/Implies
new file mode 100644
index 0000000000..abcbadb25f
--- /dev/null
+++ b/sysdeps/mips/mips64/n32/nofpu/Implies
@@ -0,0 +1 @@
+ieee754/soft-fp
diff --git a/sysdeps/mips/mips64/n64/fpu/s_fma.c b/sysdeps/mips/mips64/n64/fpu/s_fma.c
new file mode 100644
index 0000000000..b61fa643de
--- /dev/null
+++ b/sysdeps/mips/mips64/n64/fpu/s_fma.c
@@ -0,0 +1 @@
+#include <sysdeps/ieee754/dbl-64/s_fma.c>
diff --git a/sysdeps/mips/mips64/n64/nofpu/Implies b/sysdeps/mips/mips64/n64/nofpu/Implies
new file mode 100644
index 0000000000..abcbadb25f
--- /dev/null
+++ b/sysdeps/mips/mips64/n64/nofpu/Implies
@@ -0,0 +1 @@
+ieee754/soft-fp
diff --git a/sysdeps/nios2/Implies b/sysdeps/nios2/Implies
index 387a0ca052..7d69983412 100644
--- a/sysdeps/nios2/Implies
+++ b/sysdeps/nios2/Implies
@@ -1,3 +1,4 @@
 wordsize-32
+ieee754/soft-fp
 ieee754/dbl-64
 ieee754/flt-32
diff --git a/sysdeps/nios2/s_fma.c b/sysdeps/nios2/s_fma.c
deleted file mode 100644
index d9613fa67c..0000000000
--- a/sysdeps/nios2/s_fma.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <soft-fp/fmadf4.c>
diff --git a/sysdeps/nios2/s_fmaf.c b/sysdeps/nios2/s_fmaf.c
deleted file mode 100644
index aa5c9b2d91..0000000000
--- a/sysdeps/nios2/s_fmaf.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <soft-fp/fmasf4.c>
diff --git a/sysdeps/sh/nofpu/Implies b/sysdeps/sh/nofpu/Implies
new file mode 100644
index 0000000000..abcbadb25f
--- /dev/null
+++ b/sysdeps/sh/nofpu/Implies
@@ -0,0 +1 @@
+ieee754/soft-fp
diff --git a/sysdeps/sh/s_fma.c b/sysdeps/sh/s_fma.c
deleted file mode 100644
index d92438d448..0000000000
--- a/sysdeps/sh/s_fma.c
+++ /dev/null
@@ -1,5 +0,0 @@
-#ifdef __SH_FPU_ANY__
-# include <sysdeps/ieee754/dbl-64/s_fma.c>
-#else
-# include <soft-fp/fmadf4.c>
-#endif
diff --git a/sysdeps/sh/s_fmaf.c b/sysdeps/sh/s_fmaf.c
deleted file mode 100644
index 3b811ae6da..0000000000
--- a/sysdeps/sh/s_fmaf.c
+++ /dev/null
@@ -1,5 +0,0 @@
-#ifdef __SH_FPU_ANY__
-# include <sysdeps/ieee754/dbl-64/s_fmaf.c>
-#else
-# include <soft-fp/fmasf4.c>
-#endif
diff --git a/sysdeps/tile/Implies b/sysdeps/tile/Implies
index 5b29b26128..1cbc053905 100644
--- a/sysdeps/tile/Implies
+++ b/sysdeps/tile/Implies
@@ -1,2 +1,3 @@
+ieee754/soft-fp
 ieee754/dbl-64
 ieee754/flt-32
diff --git a/sysdeps/tile/s_fma.c b/sysdeps/tile/s_fma.c
deleted file mode 100644
index d9613fa67c..0000000000
--- a/sysdeps/tile/s_fma.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <soft-fp/fmadf4.c>
diff --git a/sysdeps/tile/s_fmaf.c b/sysdeps/tile/s_fmaf.c
deleted file mode 100644
index aa5c9b2d91..0000000000
--- a/sysdeps/tile/s_fmaf.c
+++ /dev/null
@@ -1 +0,0 @@
-#include <soft-fp/fmasf4.c>